Premixing combustion chamber



May l, .1951 R. H. GODDARD 2,551,112

PREMIXING COMBUSTION CHAMBER Filed Sept. 5, 1946 Patented May l, 1951 Robert H. Goddard,

I Md., by Esther vvC fG Mass.,iassignor.v of.

ideceasedflate vof l'Annapolis' oddard, executrx, Paxton, .one-half to 'TheiDaniel and Florence Guggenheim` Foundation, :.N ew York, N. Y., :a corporationv ofrNeW York.

Y Apmicatmasetember 5, 194s, summa-"694,921

` ,zyoiaims o1.fso.-ff44) JIhis invention relates -to chambersh-aving. separate :pr-emixingand-combustion 4portions `-and -adapted'fforfuse in rockets or other `propulsion apparatus Uand in ywhich gaseous or vaporize'd combustion elements lareleffectively premixed be- "fore-.admission'to thatpart of'A the' combustion chamber in which combustion takes place.-

4 .Itisthe generalob'ject of the invention to pro- :videimproved meansfforpremixing thefuel and the l.oxidizing agentand for' preventing flashback to the inner chamber portion where premixing takes place.

4 Affurther .object is toprovide improved feeding devices for use in such a premiiging'gchamber portion.

The invention further relates to arrangements andi-combinations of parts *which will behereinafter described and-more. particularlyf'pointed out infitheappended claims. f

.Preferredsforms ofthe invention arewshownfin the drawing, in-which f -Figalis a side elevation, 4partly in section,` of a chamber embodying the invention; f

Fig. 2 is a perspective View of certain parts shown in Fig. 1;

Fig. 3 is a fragmentary perspective view of a portion of a porous partition;

Fig. 4 is a partial edge View of another type of partition;

Fig. 5 is a sectional side elevation of portions of a chamber showing a modied premixing construction;

Fig. 6 is an end View of the volute and hollow perforated partition shown in Fig. 5, and looking in the direction of the arrow 6 in Fig. 5; andl z Fig. '7 is a View similar to Fig. 5 but showing a curved hollow perforated partition.

Referring to Figs. l, 2 and 3, a chamber C is enclosed by a jacket casing providing jacket spaces 2| and 22 separated by longitudinal partitions 23. The jacket space 2| receives one combustion liquid under pressure through a feed pipe 24, and the other jacket space 22 receives a second combustion liquid under pressure through a feed pipe 25.

The combustion liquids are vaporized in the jacket spaces 2| and 22 and are delivered through tapered feed pipes and 3| to longitudinally disposed tapered distributing pipes 33 and 34 which extend alongside the inner or premixing portion 35 of the chamber C. The pipes 33 extend rearward and the pipes 34 extend forward and the taper of these pipesgradually reduces the cross section in the direction of flow, thus providing uniform distribution.

"The'fpipes 33 and -34 are each provided fa y'plura-lityiof tapered fspray'pipes 40 'or 40ceq-Salter,- nately arrange'd'as v*shown in Fig; 2. `Thespray pipes -4'0 and 40a tare positioned "in .tW-ojaXial planes .perpendicular `to each other, 'and vfthe ypipes 4 ll f-andfiila -arealternately arranged ineach fpla'ne. f Y

vEach 1 pipe 240 lor 40a Ahas-"slots or spray rope'nings i throughout .itslength and these slots Aor openings in adjacent spray pipes are `oppo'sitefto `each other Aand are `'all fe'qually -spaced fapart. Very complete fpremiXin-'g `and -intermingling' f ,thewaporizedcombustion Yelements is rthus ef- =fectedlin the inner chamber portionf35. 'Y `"Substantial"pressure is maintainedinthe inner chamber portion i135, so that the -intermingled 'gases :are -rforced `through successive wire yscreens t l, 24 2. 'and e3 `and lthenthroughv a: relatively thick zperforated partition .44 into .the combustion" por- .itionfof-"the vchamber Cv-where they areignitedfby a sparkplugf4-5=zorin any other "convenient `-Inannerr-1" I The partition .44 may Jae kmade as ind-icatedfin Fig. 3 and may comprise a relatively thick disc of metal having a multiplicity of ne holes or perforations extending through the metal. Such a disc might be made by introducing ne laments into a cast metal disc and thereafter dissolving out the filaments. Turbulence andeddies occasioned by the passing of the gases or vapors through the screens and partition increase the effectiveness of the premixing.

In Fig. 4, a modified disc construction is shown in which the disc 46 is formed of thin ,metal strips 41 rolled up to form a relatively close spiral.

If the pressure in the inner of premixing chamber portion 35 is maintained substantially above the pressure in the outer or combustion portion, the premixed and intermingled gases willmove quite rapidly through the screens 4|, 42 and 43 and through the disc or partition 44. Flash-,back from the outervchamber portion to the `inner chamber portion will be practically avoided by this rapid movement. Should a flash through the partition 44 occur, it will be restricted by the wire screens 43, 42 and 4| successivelly, so that it will be substantially impossible for fire to be communicated to the premixing portion'of the chamber.

In Figs. 5 and 6, a modied construction is shown in which gaseous fuel is fed to an inner chamber portion 50 in any convenient manner, and an oxididing liquid or vapor is fed through a pipe 5| (Fig. 6) to a volute 52 from Which'it is delivered to a hollow partition 53.

3 This partition 53 is provided with relatively large passages 55 through which the gaseous fuel, after passing through screens 54, enters the chamber portion C' in which combustion takes place. The hollow partition 53 also has a large number of iine Spray openings 51 in that wall of the partition which is ,adjacent to the combustion portion C` Screens or perforated partitions 58 are preferably interposed between the hollow partition 53 and the chamber portion C. Consequently, sprays of oxidizing lid-uid or vapor are delivered into the chamber portion C' and are intimately intermingled with the streams of vaporized fuel enteringA through the openings 55. Very effective mixingr Vand intermingling of the combustion elements is thus effectively accomplished prior to combustion of the mixture in the chamberportion C.

In Fig. 7 a quite similar construction is shown,

except that the hollow partition 60 is formed with a concave surfacetoward the combustion portion C2, so that the intermingled combustion elements are directed to a focus ll at the axis of the chamber portion C2 and relatively remote from the wall of the chamber whichis shown as provided with a thin refractory lining 52. A

volute 63 is provided, as in the construction" -shown in Figs, 5 and 6.

In place of the wire screens 54 and 58 shown in Fig. 5, layers of porous orv sintered metal 65 and 66 may be substituted. These maybe formed from ne copper filings or finely precipitated copper.

The modified Aconstructions shown in Figs. 5, 6 and 7 are not specifically claimed herein but form the subject matter of a divisional application, Serial No. 137,112, filed January 6, 1950.

Having thus described the inventionrandthe advantages thereof, it will be understood that the invention is not to be limited to the details herein disclosed, otherwise than as set forth in the claims, b ut that `what is claimed is:

1. In a chamber for combustion apparatus comprising' an enclosing casing, partition means in said casing separating said chamber into an inner premixing portion and an outer combustion portion but permitting passage of premixed combustion elements therethrough, means to feed liquid combustion elements to said premixing portion, and means to ignite said mixed combustion elements in said outer combustion portion, that improvement which comprises feeding means for one combustion element having a plurality of spaced perforated feedingI tubes extending transversely across said inner premixing portion in one direction and in a plane substantially parallel to the chamber axis, and feeding means for the other combustion element having a plurality of spaced perforated feeding tubes extending transversely across said inner premixing portion in the same plane but in the opposite direction and alternating with said irst-mentioned feeding tubes.

2'. The combination in a chamber for combustion apparatus as set forth in claim 1, in which thegfeeding means includes an additional set of perforated feeding tubes for each combustion elemerit, and in which all of said additional feeding tubes are positioned in a second plane which is at a *substantial angle with the plane of said first set of feeding tubes.

y. ESTHER C. GODDARD, Executrz'rc of the Last Will and Testament of Robert H. Goddard, Dceaseda.

REFERENCES CITED Thefollowing references are of record in the lerof this patent:

r UNITED STATES PATENTS Number 

